Tonic pupil, left eye

This code describes a neurological condition affecting the left eye, characterized by a pupil that is larger than normal, reacts slowly to light, and constricts slowly to accommodation (near vision). It results from damage to the parasympathetic innervation of the pupil, often due to ciliary ganglion dysfunction.

Use this code when documentation specifies tonic pupil affecting the left eye. This diagnosis is typically made during an ophthalmic examination, noting the characteristic pupillary responses and potentially associated symptoms like blurred vision. Supporting documentation includes ophthalmologist notes detailing pupillary examination findings.

• Ensure laterality is clearly documented as "left eye" to support this specific code.
• Distinguish from other pupillary abnormalities like anisocoria (unequal pupil size) without the characteristic tonic reaction.
• Do not use for Adie's pupil if the laterality is unspecified or bilateral.